How to Divide Lavender Plants
The best times to divide lavender are fall and spring. However, to add more plants to your garden, taking cuttings. While it is possible to divide lavender, the stress may stunt the plant's growth or even kill it. You should only divide lavender plants grown in warm climates. The colder the weather, the less likely the lavender plants will survive.
Dividing lavender should only take place in fall or spring, and only plants at least 3 years old should be subjected to the process. Plants that are ready to be divided have brown, dying centers and new growth sprouting from the edges.
Cut runners from the main plant.
Look closely at the center of the plant. Some of the center branches will have taken root. Divide and remove only the sections of the plant that have one or more rooted branches.
Dig the lavender division's new hole; it must be 12 inches deep and at least as wide as the division's root ball. Line the hole with organic compost.
Dig out the division. Insert the shovel where you want to make the division. Dig deeply enough to reach below the lavender's root system on all sides. Cut away the part of the parent plant attached to the division.
Fill the new hole with excavated soil and plant the divided cutting at the same depth as the original plant.
Fill the empty space near the parent plant with any remaining excavated soil or commercial potting soil.
Water the newly planted division only when the soil dries out; the plant should be established in roughly one week. Resume a normal watering schedule once the division sprouts new growth.